Mercury switch



Oct. 4, 1932. CRAMBLET 1,880,830

MERCURY SWITCH Filed Aug. 20, 1927 3 Sheets-Sheet l l n l INVENTOR. flea 4 W if? K A TTORNE Y.

Oct. 4, 1932.

P. K. CRAMBLET 1,880,830

MERCURY SWITCH Filed Aug. 20, 192 3 Sheets-Sheet 2 INVENTOR,

' ATTORNEY.

Oct. 4, 1932. P. K. CRAMBLET MERCURY SWITCH tt 3 Shee s S ee N QAN Filed Aug. 20 192 INVENTOR. v

A TTORNE Y.

Patented ct. 4, 1932 PAUL K. CRAMBLET, OF MILWAUKEE, WISCONSIN, ASSIGNOR, BY MESNE ASSIGNMENTS,

1'0 MINNEAPOLIS-HONEYXVELL REGULATOR COMPANY, OF MINNEAPOLIS, MINNE- SOTA, A CORPORATION OF DELAWARE MERCURY SWITCH Application filed August 20, 1927. Serial No. 214,373.

This invention relates to mercury switches and operating mechanism therefor.

One object of the invention is to provide a mercury switch which is so constructed and organized and so operated as to be capable of successively making and breaking one, two, three, four or more electrical circuits in a rapid though certain manner whereby the mercury switch may be utilized as a sign flasher and to control the operation of the so-called chasing border of an electric sign. The switch also possesses capability of use in various other diverse applications.

Another object of the invention is to provide a mercury switch of the character which has a wide speed range and which may be smoothly and easily operated at high speed.

A further object of the invention resides in the provision of a switch having these advantages and capacities and which avoids the necessity of contact rings or segments, brushes, and the like, and which invgeneral presents a construction and organization that is simple, durable, comparatively inexpensive to manufacture and reliable and effective in operation.

A further object is to provide a mercury switch having a soft glass outer envelope through which the electrodes are sealed and which has hard glass sleeves so supported and mounted within the soft glass outer en velope as to serve the dual purpose of protecting the soft glass outer envelope from the arcs and of insulating the electrodes with which they are associated from the free body of mercury in the outer envelope when this is desirable during the operation of the switch.

A still further object is to provide a mercury switch of the character referred to in the preceding paragraph and wherein the sleeves are mounted in a novel and effective manner on the seals provided for the electrodes.

Other objects and advantages reside in certain novel features of the construction, arrangement and combination of parts which .will be hereinafter more fully described and particularly pointed out in the appended claims, reference being had to the accompanying drawings forming a part of this specification, and in which:

Figure 1 is a view in side elevation showing one form of mercury switch and operating mechanism embodying the present invention;

Figure 2 is a plan view thereof;

Figure 3 is a view thereof in end elevation;

Figure l is a detail view in diametrical vertical section illustrating the mercury switch shown in Figures 1, 2 and 3;

Figure 5 is a detail view in section on line 5-5 of Figure 4:;

Figures 6 and 7 are sectional views similar to Figure 4 and illustrating different types of mercury switches which may have the novel sleeve mounting illustrated in Figure Figure 8 is a detail view illustrating the change speed gearingemployed between the armature shaft of the motor and the driving disc;

Figure 9 is a fragmentary View in vertical section on line 99 of Figure 10;

Figure 10 is a fragmentary plan view illustrating parts shown in Figure 9; and

Figure 11 is a diagrammatic view showing, as an example, one set of circuits that may be employed.

Referring to the drawings and more especially to Figures 1 to 5, inclusive, the numeral 1 designates generally amercury switch. As shown to advantage in Figures 4 and 5, the switch 1 comprises an outer envelope 2 which may be constructed of soft glass. Electrodes 3, 4, 5, 6 and 7 extend in through the base of the envelope 2 and are supported in seals 8 which are constituted by integral inward projections or bosses on the base of the soft glass outer envelope. Sleeves 9' surround the electrodes 3, 4, 5 and 6 and are supported on the seals 8 by annular supporting rings and closures 10 may be constituted of insulating asbestos cement or of any other suitable material. These rings 10 serve the dual purpose of closing the lower ends of the sleeves 9 and of providing a yieldable support for these sleeves on the seals 8. The sleeves 9 are of hard glass, quartz or the like, and it is to be understood in this connection that in the specification and claims wherever these sleeves are referred to as being of hard glass, other equivalent materials are contemplated. Thehard glass sleeves have a different co efficient of expansion from that of the soft glass outer envelope but the supporting rings is left exposed, that is, Withouta sleeve.

As shown in Figure 5, the electrodes 3, 4, 5 and 6 and the wells defined by their sleeves are arranged in a circular series within the outer envelope and are spaced from the center thereof and are located at angular intervals with respect to each other. With a mercury switch of this character if suitable motion is imparted to the outer envelope the free portion F of the body of mercury may be caused to successfully unite with the portions P of the mercury located in the wells surrounding the electrodes 3, 4, 5 and 6.

The novel organization of the sleeves with the electrodes and with the outer soft glass envelope is capable of being embodied in various types of mercury switches.

Figure 6 illustrates a mercury switch S having a soft outer glass envelope shaped to provide wells W and WV. Electrodes E and E extend into the wells through seals 8' similar to the seals 8 shown in Figure 4. Sleeves 9 are mountedon these seals 8 by means of mounting rings of asbestos cement, or the like, designated at 10 and similar to the rings 10 of Figure 4, except that theyare somewhat larger. This switch S also includes an electrode G constantlyimmersed in a body of mercury designated at B. In Figure 7 a different type of switch S is illustrated, and, as in the previous instance, has an electrode H extending in through the outer soft glass envelope through a seal 8", the seal 8 also serving as a support for the hard glass sleeve 9 through the intermediary of a mounting ring 10. In this form the body of mercury is designated at B and the constantly immersed electrode at G.

The mercury switch illustrated in Figures 4 and 5 is especially designed and ada ted for use as-a sign flasher and because 0 its capacity to successfully make and break one, two, three, four or more circuits it may be conveniently employed for controlling the so-called .chasing border of an electric sign. To operate this switch 1 without the use of contact rings, segments, and brushes, or other similar instrumentalities it is mounted on a support designated generally at 15 and consisting of a block or base 16 to which a bracket 17 is secured, the bracket 17 having resilient clips 18 which embrace and frictionally hold the switch 1. The base or block 16 rests on a driving disc 19 fixed by screws 19 (see Fig. 9) to the upper end of a' vertical shaft 20 rotatably fitted in bearing openings provided therefor in an adjustable bearing 21. The bearing 21 rests on a baseplate '22 and is held in adjusted position by clampscrews 23 which extend through slots 24 in an angle bracket, guide .or holder 25 fixed to the base 22.

The base or block 16 is eccentrically pivoted on the driving disc 19 by means of a stud 26 having its head received in a countersunk opening in the top of the block and bearing on a plate or Washer 27. The stud 26 extends through a bushing 28 provided in the block 16 and is threaded in the upper end of the shaft 20 (see Fig.9). The underside of this block 16 is provided with a circular recess to accommodate the screws 19 which fasten the driving disc 19 to the upper end of the shaft 20 for rotation therewith.

Means is provided for holding the block 16 a ainst rotation about its own axis while leaving it free to revolve eccentrically with respect to the axis in the shaft 20, and this means may comprise an arm 29 fixed to the block 16 and projecting therefrom, this arm 29 operating in a slot 30' of a guide block 30 secured to the upper end of a bracket arm 31 which is supported on the bearing 21.

An electric motor 35 is fastened to the baseplate 22 and its armature shaft 36 projects below the driving disc 19. A11 intermediate friction pinion or gear 37 is positioned to engage the armature shaft 36 and the underside of the driving disc 19 and for this purpose the pinion 37 is rotatably mounted on the upper end of a swinging standard 38 pivoted as at 39 to the base-plate 22 and held in engagement with the armature shaft 36 by means of a retractile coil spring 40. The weight of the driving disc 19, its shaft 20, and the parts carried by the driving disc is sufiicient to insure proper engagement between the driving disc 19 and the pinion or gear wheel 37.

By loosening the screw 23 and adjusting the bearing 21 along the bracket 25 the disc 19 may be positioned to locate the gear wheel 37 at different distances from axis of rotation of the driving disc 19 whereby the speed with which the driving disc is driven from the armature shaft 36 may be varied.

The electrodes 3, 4, 5, 6 and 7 are connected by means of flexible wires 45 to fixed terminal bars 46 mounted on an insulating strip 47 carried by brackets 48 which upstand from the base-plate 22. Suitable wires 49 connect these terminal bars 46 with the lamps of the sign. The conductors 45, 46 and 49 as illustrated diagrammatically in Fig ure 11 are indicated by reference characters C, and, as illustrated in the diagram, the electrodes 3, 4, 5 and 6 are connected by these conductors C with one side of the lamps 3', 4: 5 and 6'. The opposite sides of the lamps are connected to a wire C which leads to the negative source of current. The positive source of current is connected by a wire C" with the electrode 7. The free portion F of the mercury switch is of such quantity with respect to the size of the outer envelope and the spacing of the electrodes as to simultaneously unite with the portions P in three of the wells or sleeves 9 while being spaced from the mercury P in the other well. This may be varied, however, to cause the free portions F to unite with the mercury in any desired number of wells. Thus, as illustrated in Figure 11, the mercury F bridges the electrodes 7, 6, 5 and 4. This energizes all of the lamps 6, 5 and 4' but leaves the lamps 3 extinguished. As the mercury travels around the envelope it breaks away from the mercury surrounding the electrodes 6, 5, 4 and 3 in the order named, and thus, the lamps are lighted in such an intermittent order as to give the desired chasing effect. The eccentric movement imparted to the support 16 causes the switch to revolve in an endless path without tending to wind or entangle the flexible lead wires 45. This motion of the switch displaces the free portion of mercury outwardly and upwardly under the action of centrifugal force to cause it to travel around over the circular series of electrodes in the manner described. With this mode of operation a very rapid yet smooth action is had and yet the control of the multiple circuits is accurate, reliable and efiective.

The speed of operation of the switch may also be varied and, as illustrated, the variable speed may be had by means of a mechanical speed change device. In some instances, however, it may be advisable and desirable to omit the mechanical speed change device and vary the speed of the electric motor in any suitable way, as, for instance, by interposing a variable resistance in the motor circuit. Control of the speed by varying the speed of the electric motor is contemplated by the present invention.

The invention claimed is:

1. A mercury switch comprising an outer envelope of soft glass, a plurality of electrodes sealed in through the glass of the outer envelope, sleeves of hard glass supported within the outer envelope, surrounding said electrodes and defining wells in which the electrodes within the sleeves are contained, a body of mercury having portions filling the wells and also having a free portion which successively unites with the portions filling the wells, one of said electrodes being constantly immersed in the free portion, and

means for bodily and eccentricall moving the switch to give the desired motion to the free portion of the mercury.

2. Operating mechanism for a mercury switch of the type having an envelope, a plurality of electrodes therein, and a body of mercury successively cooperable with the electrodes when displaced angularly around the envelope and comprising a support for the switch, a driving disc to which the support is eccentrically connected, means for preventing the support from rotating about its own axis while leaving it free to bodily and eccentrically revolve, an adjustable bearing for the axis of the driving disc, and a motor driven gear wheel cooperable with the drivin disc for driving it at variable speeds depen ing upon the position of the ad ustable bearing. I

3. Operating mechanism for a mercury switch of the type having an envelope, a plurality of electrodes therein, and a body of mercury successively cooperable with the electrodes when displaced angularly around the envelope and comprising asupport for the switch, a driving disc to which the support is eccentrically connected, means for preventing the support from rotating about its own axis while leaving it free to bodily and eccentrically revolve, an adjustable bearing for the axis of the driving disc, and a motor driven gear wheel cooperable with the driving disc for driving it at variable s eeds depending upon the position of the ad uStable bearing, and means for yieldably maintaining the motor driven gear wheel operatively positioned.

In witness whereof, I hereto aflix my signature.

PAUL K. GRAMBLET. 

